Objective:

Poor indoor air quality in the workplace, public buildings, and residential dwellings has the potential to adversely impact human health. Polar, volatile organic compounds are common contributors to indoor air pollution, and formaldehyde and other aldehydes are among the most studied indoor environmental pollutants as a consequence of their ubiquity indoors and established human health significance. Adsorption-based treatment strategies offer an attractive alternative to both energy-intensive ventilation and impractical source removal. The focus of this research is to develop, through experimentally-based research, a mechanistic understanding of the sorption interactions between polar, gas-phase organic pollutants and the surfaces of adsorbent media used in air treatment systems. This work will strengthen efforts to protect public health in indoor environments by reducing environmental exposure to harmful indoor air pollutants.

Synopsis:

This work addresses a need to provide people with clean, indoor air by reducing their exposure to harmful aldehydes. The project consists of three main tasks: 1) physical and chemical characterization of activated carbon adsorbents, 2) adsorption equilibrium and desorption studies, and 3) mathematical modeling of the sorption processes observed. The outcome of this work will be a predictive tool for assessing the performance of adsorption-based media for gas-phase treatment of indoor air.

Approach:

This research project consists of three main tasks: 1) physical and chemical characterization of both commercial and synthesized activated carbon adsorbents using a variety of surface analytical techniques, 2) adsorption equilibrium and desorption studies in differential batch reactors and columns, and 3) mathematical modeling of the sorption processes observed.

Expected Results:

This research project will identify specific chemical and physical characteristics of activated carbon surfaces that promote the removal of gas-phase, polar organic pollutants. It is expected that basic and acidic functional groups will influence aldehyde adsorption through distinct sorption mechanisms, depending on indoor environmental conditions, such as relative humidity and temperature. By precisely describing molecular-level sorption interactions over a range of environmental conditions, the outcome of this work will be the development of a predictive tool for assessing the performance of adsorption-based media for gas-phase treatment of indoor air.

Potential to Further Environmental/Human Health Protection:

This work should serve as a model approach for evaluation and/or design of indoor surfaces and their potential for pollutant removal. Gas-phase sorption processes greatly influence the mobility and distribution of many indoor contaminants, but these processes are not yet well characterized for indoor environments. In response to the need for sustainable, healthy building materials, these studies will underscore the value of concurrent physical/chemical surface characterization and adsorption/desorption studies by contributing to knowledge of gas-solid sorption mechanisms. On a larger scale, this work should further the development of materials that live up to the principles of green engineering and ultimately minimize human exposure to indoor pollutants.

Progress and Final Reports:

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.